Thermionic device



1,514,898 G. L.4 GEISEY THERMIONIC DEVICE Filed July 13. 1923 2 ShewtB-Shee.. l

G. L. GEISEY THERMIONIC DEVICE Filed July 18 1923 2 Shoots-Sheet 2 esoneri L. cursar, or STEUB'ENVILLE, omo.

ERMIONIC DEVICE.

Application led July 18, 19,23.. Serial No. 659,418.V

. To all whom it may Gander/rt:

and useful Improvements in Thermionic Devices, of which the following isY a specifica-v tion.

` disclosed in my pendin similar invention, filed This invention relates to an improved thermionic device of the general character application for a ovember 20, 1922, Serial Number 602,197, and seeks, among other objects to provide a thermionic device embodying a simplified mounting for the plate and grid of the device. Q

A further object is to provide a device whereby the plate and grid may be readily assembled in position, thus reducing the cost of manufacture of the device, and wherein the plate and grid will be rigidly sustained. Another object of the invention, in this connection, is to provide a device wherein, by rigidly sustaining the plate and grid, uniform spacing therebetween bemaintained.

And the invention further comprehends a novel process for making the grid and plate in manufactura j Other and incidental objects will appear hereinafter. v 4 t In the drawings:

Figure 1 is a perspective view of my improved thermionic device, the containing vessel being broken away,

Figure 2 is an enlarged vertical detail sectional view taken between the grid surfaces of the device,

Figure 3 is a vertical detail sectional view on the line 3 3 of Figure '2, looking inthe,l

direction of the arrows,

Figure 4 is an enlarged detail sectional View showing the plate and grid structure of the device, j c

, Figures 5, 6"and'7 are plan views showing the steps followed informing the double grid of the device, and

Fi res 8, 9 and 10 are plan views show- .ing t e steps followed in forming the double plate employed.

Referring to the drawlngs, the numeral 10 indicates an evacuated containing vessel and upstanding within the vessel is an insulating stem 11. Extending through the stem near one edge thereof is a plate lead '.12- bent laterally at its upper end portion to form a support' 13- and embedded in the stem near its opposite edge is a similar support 14. Welded or otherwise secured at their. lower ends to said supports are spaced parallel wire supporting elements or posts 15. kExtending through thest'em adjacent the post 14: is a grid lead 16 bent laterally at its upper end to form a support 17 and embedded in the sten. adjacent the lead l2 is a similar support 18. Welded or otherwise secured at their lower ends to the supports 17 "and 18 are spaced parallel'wire supporting elements or posts 19 to thefupper end 'of one of which is fixed a glass bead 20 and embedded at one end in said bead is a lat-l erally directed arm 21. The arm21 is also preferably formed of a short length of wire,

being insulated from said post by the bead,

and welded or otherwise secured to the free end of the arm is a. depending h'ook 22 disposed substantially midway between the posts. Extendingethrough the stem between the lead 16 and support 18 are spaced cathode leads 23 deiected laterallyl away from each other at their upper ends and suitably secured a-t its extremities tothe upper ends of said leads is a flamentary cathode 24 engaged over the hook 22 and supported thereby.

Mounted upn the posts 15 is a double l output anode or plate comprising spaced parallel plate surfaces 25 and mounted upon the posts 19 between said anode and the cathode is a double control electrode or grid comprising spaced grid surfaces 26 lying at opposite sides of the cathode parallel thereto and to the plate surfaces 25. As particularly brought out in Figure 2, the grid surfaces are checkered with a plurality of regularly spaced openings 27 and while the plate ,surfaces are mounted close to the grid surfaces, still, in order to decrease the distance between the working faces of the plate lsurfaces and the cathode, I emboss or stamp the plate surfaces with checkered groups of regularly spaced projections 28 registering with the openings 27 to extend toward the cathode opposite said openings. The projections 28 correspond in shapejand number to the openings 27 and, as shown in detail in Figure 4, the end walls 28 of said projections, which end walls form the effective or working faces of the plate surfaces, are advanced toward the cathode a distance equal to the height of said projections to eliect a corresponding increase in the current and voltage output of the device, said end wallsy being but slightly spaced from the grid sur` faces. The late and grid are preferably of substantia ly pure molybdenum. I havev discovered that this metal gives olf less gas under hea-t than metals now in common use for the same purpose with the result that the containing vessel 10 is, inl the'inanufacture yof the device, moreA easily evacuated while a correspondingly less amount of gas is generated in the Vessel during the practical operation of the device. In Figure 1 of the drawings, l have shown the containing vessel 10 mounted in an appropriate socket 29.

. longitudinally directed tongues 27 and near its other longitudinal edge with a similar pair of tongues 28. The blank is then passed through another die and, as shown in Figure 6, is formed with a central oblong opening defining the grid surfaces 26 as well as also defining straps 30 at the ends of said opening connecting the grid surfaces. li`urther, the blank is also coincidently formed with spaced rows of the openings 27 in one of the grid surfaces andl a single row of saidA lopenings in the other of the grid surfaces.

The blank is then turned over end for end from the position shown in Figure 6 to the position shown in Figure7 and fed throu h the same die used in the stepI typifiedin Figure 6. Thus, as will be seen, in the step typified in Figure 7 a single row of the openings 27 `is formed in one of the grid surfaces between the double row produced in the step of Figure 6 While a double row of said openings is 4formed in thel other of the grid surfaces at opposite sides of the single row produced in the step of Figure 6'. The completed grid as shown in Figure 7, is'aecordingly forme by the use of but two dies.

' The plate is, as shown in Figures 8, 9 and 102 formed in a manner similar to the grid, belng, like the grid, stamped from a ribbon of sheet material ofthe character noted. In practice, the ribbon is fed through a die to produce an oblong blank, as shown in Figure 8, this blank being provided at one longitudinal edge thereof withv a pair of longitudinally directed tongues 32 and atits opposite longitudinal edge with a similar pair of tongues 33. The blank isy then fed through a second die and is formed with a central oblong opening defining the plate surfaces 25 as well as straps 35 at the ends `of said opening connecting said surfaces.

The blank is then fed through a third die to form the plate surfaces with the projections 28.l Thus, in forming the plate, three separate dies are used.

ln assembling the device, the straps 30 of the grid are bent around one of the posts 19 when the grid surfaces 26 are brought into.

parallel relation at opposite Asides of the cathode 24. The pair of tongues 27 is then bent in overlapping relation about the other of the post 19 as is also the pair of tongues 28. when the tongues and said straps are Welded to theposts, this operation serving,

posts, the' tongues of each pair' bein thus' secured together so that the plate, li e the grid, will also be rigidly mounted. As will be seen, the grid and plate may thus be readily mounted in position and since both the grid and plate are constructed of sheet metal, the grid surfaces and plate surfaces will retain their parallel relationship and will, furthermore, be free from vibration when the device is in operation. The-oVer-,

lapping tongues of the plate'are arranged opposite the overlapping tongues of the grid 1 and, preferably, the plate is of slightly greatersheight than the grid.

Having thus described Vtige invention,"

what is claimed as new is:

1. The method of forming a therinion'ic device electrode which consists in stamping a blank having companion electrode portions, punching one of said portions to form an opening and punching the other of Said portions to formspaced openings, and turning the blank over end for end and punching said first mentioned portion to form spaced openings at opposite sides of a plane occupied by the initial opening therein and punching said second mentioned portion to form an opening between planes occupied by the initial spaced openings therein.

2. The method of 'forming a thermionic device electrode which consists in stamping a blank having tongues at inner end thereof, perforating the blank to define com'- panion electrode portions as well as to definev straps connecting said portions and coincidently punching one of said portions to form an opening and punching the other of said .portions to form spaced o enings, and turning the blank over end or end and punching said first mentioned portion to form spaced openings at opposite sides of a plane. occupied by the initial` opening therein and punching said second mentioned portion to form an opening between planes occupied by the initial spaced openings therein. i

3. rihe method oi making an electrode unit ci a thermionic discharge device which consists in stamping Aa blank to provide companion'electrode portions, and embossing eachoi? said portionsto provide each portion with a checkered jections.

'4. rllhe method ci making an electrode unit of a thermionic discharge device which consists in stamping a substantially oblong blank, punching said blank transversely valong a Imedial 'line to torni an opening terminating short 'ci the side edges ot the blank and dening spaced electrode surfaces united by upper-and iower reduced bendable connecting straps, and embossing each of said portions to provide each portion with a checkered group of projections.

5. 'llhe method of making an electrode unit of a therinonic discharge device which .consists in stamping a blank to provide companion electrode portions, y and punching each, 'of said portions to provide each portion* with a checkered group of openings.

6. The method oi making an electrode unit of a thermionic. discharge device. which consists in stamping a substantially oblong blank, punching said .blank transversely along a medial line lto form an opening' terminating short ofthe side edges oi the blank 4and defining spaced electrode sur- I .faces united by upper and lower reduced bendable connecting straps, and punching each of .said portions to provide each ,por-

l tion with a checkered group of openings.

7L The method of making an audion which consists in stam ing a substantially oblong blank provid with reduced bendable tongues, punching said blanktransversely along a medial line to form an opening 'terminating short of spaced g the sides edges lof the blank and defining spaced electrode surfaces united -by upper and lower 'reduced bendable connecting straps, transversely "bendin the straps about a post to is'pcse, said surfaces 1n ing sai tongues Aabout another post, and welding said ,straps and 'tonga` posts for connecting the unit therewith.'

'long sheet metal electrode unit group of proy at one end edgek parallel relation, transversely bendA es tothe 8.- i'n a therinionic device, o stamped obable straps integrally connecting said suia'ces, said surfaces being checkered with raised portions.

l0. in a'thermionic device, a. cathode, a stamped oblong sheet metal electrode unit provided at one end with reduced bendable tongues and formed 'with a medial provided at.

tilltransverse aperture terminating short ot the side edges of the, unit to define oompanion plate surfaces integrally united by reduced -upper and lower bendable connecting straps dexed to dispose said surfaces in parallel relation at opposite sides of the'cathode, a pair of spaced vertical posts one embraced by said straps and the other having said tongues' exed thereabout supporting said unit, a Second stamped oblong sheet metal electrode unit provided .at one end with reduced bendable tongues and formed with a medial transverse aperture terminatin short ot the side edges of s 'uch unit to de 1e companion grid surfaces integrall united by reduced uper and lower benda le connecting straps exed te pose said grid surfaces in parallel relation lying between the plate surfaces and `the cathode, anda second pair of spaced vertic al posts one embraced by the straps of. the latter unit and the other having'the tongues of suchA unit exed thereabout supporting said latter unit, the grid surfaces being checkered with openings andthe plate sur# faces being checkered with raised portions extending toward the cathode opposite said openings respectively.

In testimony whereof l affix my siature.

' GEORGE-L. GEISEY. A[1.. s.)

dis- 

